Means for lowering loads



Nov. 25, 1969 D. w. COOPER 3,430,108

. MEANS-FOR LOWERING LOADS Filed Oct. 16, 1967 4 4 Sheets-Sheet 1 o 0 VIII/QW n nvenlor Attorneys Nov. 25, 1969 D. w. COOPER 3,480,108

MEANS FOR LOWERING LOADS Filed oct. 16. 1967 4'sheets-sneet z Inventor DANI-EL WUMSLD COPER mmm A Harney-- Nov. 25, 41969 D. w. cooPER 3,480,108

MEANS FOR LOWERING LOADS Filed Oct. 16, 1967 4 Sheets-Sheet 3 Inventar DAN/EL mur/SLU COOPER M u ma A ttorneys Nov. 25, 1969 D. w. COOPER MEANS FOR LOWERING LOADS 4 Sheets-Sheet 4 A ttorn e y;

United States Patent O U.S. Cl. 182-133 4 Claims ABSTRACT F THE DISCLOSURE A device with rope clamping means and with a load attached thereto clampingly engages a vertical rope and moves downward therealong. The degree of friction or clamping pressure exerted on the rope is controlled by a lever mechanism operating on the clamping means. Separate adjustable means carried by the clamping means also is employed for fixing the degree of friction or clamping pressure on the rope to regulate the speed of descent of the device and load carried thereby.

The invention comprises a means for descending a rope or length of webbing and consists of a braking unit to which the man or other load is attached, the unit having balls or pressure pads which are moved towards or away from the rope by a lever mechanism which can be operated whilst the unit is moved down the rope to control the rate of descent of the load.

This invention relates to means for lowering loads down a line, such as a rope or a length of webbing, the load being a person or an inanimate consignment. The invention can be used for example for lowering loads from hovering aircraft, from an oil rig or other raised platform.

The object of the invention is to provide means whereby the rate of descent of the load can be controlled by the load, and whereby descent of the load is arrested if the pressure on the control means drops below a predetermined value.

According to this invention a device for controlling the rate of descent of a load down a line, such as a rope or a length of webbing, comprises a means to engage frictionally with the said line under the effect of the said load and a lever mechanism, the rate of descent of the load being controlled by the pressure exerted on the said lever mechanism in which the descent of the load is stopped if the pressure on the said lever mechanism falls o below a predetermined value.

The means engaging the line may comprise a number of balls or pressure pads which can be moved into braking contact with the line.

The invention also comprises a method of lowering one or more loads down a line using one or more devices as defined above.

The invention is described hereinafter with reference to accompanying drawings of which FIGURE l illustrates one form of the invention, FIGURE 2 is a section on the line II-II of FIGURE l, FIGURES 3 and 4 are exterior views of another form of device according to the invention, FIGURE 5 is a sectional view of the device taken on the line V-V of FIGURE 4, FIGURE 6 is a sectional view of part of the device and FIGURE 7 illustrates an operator lowering himself on one device and controlling a second device.

The device illustrated in FIGURES 1 and 2 is designed for lowering loads down a rope 25. The device comprises a sleeve 16 covering a number of balls held in a suitable holder 15. The sleeve 16 is conical internally being of smaller internal diameter at the top than at the bottom,

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Jand is connected by pin 20 to arm 12. Arrn 12 also carries a ring 14 from which the load to be lowered, for example a man, can be suspended by a suitable harness. A lever arm 11 is also connected to the arm 12 by a pivot pin 19, the arm having a suitable handle 13 at its end remote from the pin 19. The lever arm 11 is connected to head 17 by a pivot pin 21. The head 17 carries the ball holder 15 which slides within the sleeve 16. A stop 18 is connected to the sleeve 16 to limit the movement of the sleeve relative to the ball holder. The stop 18 is screwed onto the sleeve y16 and can be moved upwards and downwards on the sleeve to control the minimum braking eiect of the device.

The ball holder 15 carries three rows of balls 22, 23, and 24. Each row comprises three balls the positions of the balls in the rows being symmetrical in each row but displaced relative to the other rows so that the balls press on different parts of the rope 25 on which the device is mounted. The balls could all be of the same size but we prefer to have the balls in the diiierent rows of different sizes, for example the balls in row 22 could each be of 7/16 inch diameter, those in row 23 could be of 3/8 inch diameter and those in row 24 of 5/16 inch diameter- The slope on the sleeve 16 could be such that the surfaces of all the balls are in contact with the rope at the same time when the rope just makes Contact with any of the balls, or the slope could be adjusted so that the top or bottom row makes contact rst and the balls in the other rows make contact only as the sleeve 16 is moved down the ball holder 15.

With this arrangement it follows that the pressure exerted by the balls on the rope 25 varies as the sleeve 16 is moved relative to the ball holder 15. The position of the ball holder 15 in the sleeve 16 depends on the position of the lever arm 11, the balls being moved away from the rope 25 as the handle 13 is lowered and towards the rope 25 as the handle 13 is raised.

If an inanimate load is being lowered on the device, the position of the lever arm 11 is adjusted by moving the stop 18 on the sleeve 16 as mentioned above and the lever is tied down against this stop, before the load leaves the discharge platform so that the degree of retardation exerted by the balls and the speed at which the device is lowered is fixed. If however a man is to be lowered on the device his weight pulling on the lower end of the sleeve 16 locks the device onto the rope. By pulling the handle 13 downwards the man raises himself and the sleeve 16 relative to the ball holder 15 and so releases the device. He can move the handle up or down as he slips down the rope and so can adjust the pressure exerted by the balls on the rope and control his speed of descent.

An operator can be lowered on the same line as an inanimate load as illustrated in FIGURE 7. ln this case the operator is attached by means of a suitable harness to device `46 on rope 44 above an inanimate load 50 which is suspended from device 47. The operator controls his own rate of descent by operating the arm 48 of device 46 with his hand. He can also control the rate of descent of the load 50 by operating the handle 49 of device 47 with his foot, the device 47 stopping on the rope 44 if no pressure is exerted on the handle 49.

The device shown in FIGURES l and 2 is suitable for use only with a rope of roughly circular cross section. A device suitable for use with lines of other shapes, for example a line of flat webbing, is shown in FIGURES 3, 4, 5 and 6.

The device in this embodiment is designed to lower loads down a strip of webbing 37. Pressure to arrest movement of the device is provided by pressure plates or slippers 36 which can be shaped to suit the particular form of line in use.

The device comprises a pair of lever arms 26, 27 which are connected to handle 28 by screws 29. The device has two side plates 30, 31 connected together by a number of bolts 32. A link 35 from which can be suspended an inanimate load is connected to one of the lower bolts 32. A person can be suspended from the device by a suitable harness attached to a link 34 which can be inserted into a closed hook 33 carried by the shorter ends of the levers 26, 27. The slippers 36 which press on either side of the webbing line 37 are attached to shoes 39'.

The assembly includes two guide rods 51 (FIGURE 5) and springs 38 which are mounted in housings in the left hand shoe 39 (FIGURE 5 No upper right hand connecting bolt 32 is provided (see FIGURE 5) so that the right hand slipper 36 and shoe 39 can be easily removed for insertion of the webbing.

The controlling pressure on the webbing is provided by screws 40, 41 which bear on the central parts of the slippers from opposite sides. Screw 40 is a presetting screw and this is adjusted before the device is released along the line. If the load to be carried is inanimate the screw 40 is set to control the rate of descent of the load. The screw is provided with a crank handle S2 for rapid adjustment of the pressure. The handle is depressible into the lever 26 to lock the screw in any adjusted position.

Screw 41 is connected to lever 27 through a shaped end 42, the lever being held to the screw by spigot 43. The pitch of screw 41 is such that a very small movement of the lever 27 is necessary to tighten the screw suiciently to stop the device and lock it to the webbing line 37.

The hook 33 (FIGURE 6) is locked in its closed position by a catch 53 held by a spring pressed plunger 54. To release the link 34 from the hook it is necessary to unlock the hook by raising the catch 53.

The operation of the device is similar to that described above for the device shown in FIGURES 1 and 2. The load of the operator on the shorter end of the lever 27 tends to tighten the screw 41 and so lock the device on the line. Downward pressure on the handle 28 moves the screw 41 away from the slipper 36. By adjusting the position of the handle 28 the operator can control the braking elfect of the slippers 36 and so his rate of descent. The operator can of course control with his foot a lower device as shown in FIGURE 7 in exactly the same manner as described above.

The device is shown as applied to a flat webbing line, which could be carried in a dispenser S carried by the device, for example by attachment to link 35 or could be carried by the load, or be attached to the harness supporting the load. If a rope is used with the device the slippers would be suitably shaped to accommodate the curvature of the ropes surface.

The device is slipped onto the line before use. The device could be made to open sufciently for a line to be slipped between the slippers if desired by arranging for the handle to be hooked onto one of the lever arms and for some of the bolts holding the side plates together to be easily removed and replaced.

When either embodiment is to be used with an inanimate load not under the control of a following opera.- tor, it is desirable to x the lever arm, for example by 4 tying the arm against the stop 18, FIGURE l, or to one of the bolts 32, FIGURE 3, before the load is released from the discharge platform.

I claim:

1. A device for carrying a load down a line, such as a rope or a length of webbing, at a controlled rate of descent, comprising a means to engage frictionally with the said line controlled by a lever mechanism which, when moved in one direction increases the friction on the said line and when moved in the opposite direction decreases the said friction, means whereby the load can be connected to the lever to move it in the direction to increase the friction and means which can be operated Whilst the load is in motion to move the lever in the opposite direction, the device moving with the load down the line, and separate adjustable means carried by the rst named means for xing the degree of friction on the line, whereby the speed at which the device is lowered is fixed.

2. A device as claimed in `claim 1 in Which the means to engage frictionally with the line comprises a number of balls carried in a housing which ride on the inner surface of the sleeve, movement of the sleeve relative to the housing altering the braking effect exerted by the said balls on the said line, and in which said separate adjustable means is carried by said sleeve.

3. A device as claimed in claim 1 in which the line is carried in a dispenser carried by the device so that the line can be paid out as the load moves down it.

4. A device for carrying a load down a line, such as a rope or a length of webbing, at a controlled rate of descent, comprising a means to engage frictionally with the said line controlled by a lever mechanism which, when moved in one direction increases the friction on the said line and when moved in the opposite direction decreases the said friction, means whereby the load can be connected to the lever to move it in the direction to increase the friction and means which can be operated whilst the load is in motion to move the lever in the direction, the device moving with the load down the line, and in which said means to engage frictionally with the line comprises pressure pads which can be moved into braking contact with the said line, one of the said pads being connected to screw means which is moved by the lever mechanism to adjust braking pressure exerted by the pads on the said line.

References Cited UNITED STATES PATENTS 1,114,832 10/1914 Whitney 182-136 1,144,702 6/1915 Forest 182-5 1,270,401 6/1918 French 182-136 1,300,752 4/1919 Mattern 182-15 1,754,132 4/1930 Bekkum 182-136 1,964,995 7/1934 McLaughlin 182-136 3,177,543 4/1965 Fountain 182-5 3,302,750 2/ 1967 Arnold 182-142 REINALDO P. MACHADO, Primary Examiner 

